Embodiments of the present invention relate generally to authenticating a document having a magnetic stripe, and more specifically to authenticating a unique magnetic characteristic of a card (e.g. a credit card).
Documents having a magnetic stripe have long been used for a variety of different purposes. Such documents are currently used in large numbers, e.g., credit cards, debit cards, I.D. cards, etc. Typically the magnetic stripes of such cards carry recorded data relating to the use of the card, and in some instances relating to the assigned user or owner of the card.
Although magnetic stripe cards are widely and successfully used in commerce and industry, counterfeiting these cards is a common occurrence, which can result in great losses. For example, if a counterfeiter obtains an authentic credit card (or the recorded data on the card), the counterfeiter can create a new credit card, which could be used to make unauthorized transactions. Consequently, the ability to reliably verify the authenticity of a card (or other document) having a magnetic stripe is important.
One method for verifying the authenticity of a card uses certain magnetic characteristics of the magnetic stripe to identify cards. Generally, the magnetic stripes of individual cards possess inherent, substantially unique, magnetic characteristics (often referred to as a fingerprint or signature). This fingerprint is related to a noise-like component that results from the manufacturing process of the magnetic stripe.
Current methods convert the magnetic noise to a binary number based on a measured magnetism of specific parts of the magnetic stripe. This binary number is then directly compared bit-by-bit to a reference binary number resulting from an original scan (measurement) of the card and/or independently to previously authenticated scans. The total of the bit-by-bit differences may then be compared to a threshold value to determine whether the card is authentic.
A problem with the current methods is that the magnetic stripe of the authentic document degrades over time and use. A result is that the ability to accurately identify the authentic document can be compromised. This is important as a part of authenticating a document is not only to identify non-authentic documents, but to also identify when the authentic document is being used.
It is therefore desirable to have methods, systems, and apparatus that continue to accurately authenticate a document having a magnetic stripe, particularly even after many uses of the document.